HP Tuners for 2005-2015

4th gear it is then. Today is Dyno day at 4pm and I want to have my junk good to go. Spice it up for me brother.

 

Is the main reason to lock up the tc in 4th for better dyno numbers? If so, wouldn't this kind of misrepresent real world numbers since you wouldn't drive it like that on the street? Or does it sometimes lock up on the street in 4th? I drive a 6 speed so I'm really just curious and trying to learn here, any info would be appreciated

 

For a dyno you want it in 1:1 gear and locked out so there is no slop between the driveline and engine.

 

Gotcha, so this would actually provide more accurate numbers for the max hp and tq it sounds like.

Any idea what would happen if you drove it on the street like that? I guess I don't quite understand how the whole lockup thing works. Im guessing there is a good bit of slip/slop during normal driving?

 

It locks and unlocks all the time depending on driving conditions. Just the logic in the trans usually doesn’t let you floor it and stay locked I think depending on what gear you are in and when you floor it.

 

shoot me your tune and ill make a dyno 4th gear lockup tune that should work for what you are trying to acomplish.

 

You can achieve 4th gear lockup pretty easy, just stick it in 4th gear and get up to ~45mph with light throttle and you will be locked. You will notice you will roll into the throttle and rpms and speed will increase at the same rate. When you are unlocked you will notice that the rpms will move up faster than then speed does.

The problem comes in when trying to dyno tune and you dont want the truck to shift or be unlocked due to extra heat in the trans / driveline losses / extra variables due to torque converter slip. And a street driveable trans tune will unlock and downshift down to 3rd or even 2nd when you go WOT from low rpms when in 4th and locked.

 

Sent you both of my tunes. I explain what is going on in the email. Thanks brother!

 

@mightytacoman I think I got it. Rev limiter has been set to 5700 and I'm seeing a peak cutoff of about 5,868 as per my latest log. I think I'll keep it there. However, with saying that, I am still not totally convinced those 12 tables must be changed in order to obtain the results needed to see the your desired redline. They may help the computer stay in control past its OE limits though that way its not blindly just exceeding known limits, similar to the way the MAF was overrunning on the smaller pulley blower trucks. I am out of time today to make changes outside of the TCC lockup file that @nd4spdbh is going to send me. If you want to give it a shot and take logs of the changes which reflect the increase without modifying the the tables today, feel free to do so and let me know.

 

Check you email, and good luck. 4th gear tcc locked wot runs from just above 1500rpms on up will put a HUGE strain on everything. LET US KNOW HOW IT GOES!

 

If it puts a strain on things do you think I SHOULD run the file while I'm there then?

 

It’s just gonna put a load on the motor. Imagine driving a manual and taking off from 3rd instead of 1st. Same thing. You’ll be safe running it locked in 4th from low rpm

 

I don't see how it would be much different than a 4th gear pull in a manual starting from 1500 RPM...?

Roll into, don't just slam WFO and should be fine

 

I mean these are the things I sort of figured, but sometimes it's best to heir on the safe side to ask just in case.

 

I would probably log on the chart vs time page engine rpm and trans input rpm with the same bounds you will see slight variances as the sensors dont read quite the same rate but if you start seeing deviations that means the TCC lockup clutch will be slipping. (you could even get fancy and do a custom math parameter comparing the two and give you a % error)

The trans should be able to handle this, but it was never tuned to be in lockup under WOT

 

Gotcha. I got your email earlier BTW. Thank you for doing that for me. I am going to be heading over to the shop I'm supposed to be at in about 5 minutes.

 

I'm FINALLY back from my backpacking trip in Northern NM! Back a day early, but what a trip.. Anyway, I'll be catching up on PM's/emails this evening/tomorrow.

 

Glad you took some time for you man! No rush on getting back, we all understand everyone has their lives outside of TW!

 

I'll admit I haven't seen a good diagram of how the torque converter lockup works, but in my head I think I was picturing it clamping together inside the torque converter kinda like a clutch and flywheel.

Is it at all like that? Is damage to the trans less likely while not locked up?

 

When switching the ECU’s and doing the relearning is it normal for the dash to be acting all crazy?